The chief cause of malignant mesothelioma cancer is exposure to asbestos, usually through inhalation. It is estimated that approximately eight million Americans have been exposed to asbestos over the past 50 years because of their occupations.
Who is at the Most Risk of Developing Malignant Mesothelioma Cancer?
Asbestos exposure happens to workers that have experienced a substantial risk for developing mesothelioma cancer. Malignant mesothelioma cancer has a latency period of approximately 30 to 40 years between exposure to asbestos and the development of the disease.
In a study titled Latency of asbestos disease among insulation workers in the United States and Canada, published December 15, 1980 in Cancer, researchers examined 2,271 recorded deaths among 17,800 asbestos insulation workers from January 1, 1967 to December 31, 1976. They observed that:
“In general, though, the period of clinical latency was 2-4 decades or more and there were important differences among the several asbestos-associated diseases. Lung cancer peaked at about 30-35 years from onset and asbestosis at 40-45 years. Each tended to decline in incidence afterwards. Pleural and peritoneal mesothelioma reached their highest incidence later than lung cancer, but the incidence did not decline.”
Does the Level of Exposure Affect the Risk of Developing Malignant Mesothelioma Cancer?
There is what is referred to in medicine, as a dose-response relationship between asbestos exposure and the development of the disease, meaning the greater the exposure to asbestos, the higher the risk of developing mesothelioma cancer.
In a study titled Environmental exposure to crocidolite and mesothelioma: exposure-response relationships, published January 1, 1998 in the American Journal of Respiratory and Critical Care Medicine, researchers tracked the location of the 4,659 residents of Wittenoom, Western Australia who lived there between 1943 and 1993 for at least 1 month and who were not directly employed in the crocidolite industry. All of those who were found were sent a questionnaire. Their asbestos exposure levels were estimated from results of environmental surveys and their duration of residence. By the end of 1993, the researchers identified 27 diagnosed cases of mesothelioma. These former residents of Wittenoom, had lived there for a longer period of time than those who didn’t develop mesothelioma, had a higher intensity of exposure, and a higher overall exposure to crocidolite, leading researchers to conclude that there is a greatly increased risk of mesothelioma cancer, which is dose-dependent.